Device, system, and method for delivery of a tissue fixation device

ABSTRACT

Systems and methods for fixating a graft in a bone tunnel are provided. In general, the system includes a tissue fixation device having a delivery configuration and a deployed configuration, at least one graft retention loop coupled to the tissue fixation device, and a drill pin having a sidewall surrounding a cavity at a proximal end of the pin and at least one longitudinally oriented opening in the sidewall in communication with the cavity, the cavity being configured to fully seat the tissue fixation device. The drill pin is configured to substantially contain therein the tissue fixation device when in the delivery configuration and to enable deployment of the tissue fixation device through the opening. Drill pins configured to contain a tissue fixation device are also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 15/154,292 entitled “Device, System, and Method for Delivery of aTissue Fixation Device” filed May 13, 2016, which is hereby incorporatedby reference in its entirety.

FIELD

Implantable tissue fixation devices as well as devices, systems, andmethods for delivering such tissue fixation devices are provided.

BACKGROUND

A ligament is a piece of fibrous tissue which connects one bone toanother within the body. Ligaments are frequently damaged (e.g.,detached, torn or ruptured) as the result of injury or accident. Adamaged ligament can impede proper stability and motion of a joint andcause significant pain. A damaged ligament can be replaced or repairedusing various procedures, a choice of which can depend on the particularligament to be restored and on the extent of the damage. When ligamentsare damaged, surgical reconstruction can be necessary, as the ligamentsmay not regenerate on their own.

An example of a ligament that is frequently damaged as a result ofinjury, overexertion, aging and/or accident is the anterior cruciateligament (ACL) that extends between a top of the tibia and a bottom ofthe femur. Another ligament that is often damaged and may need to bereplaced is a posterior cruciate ligament (PCL). A damaged ACL or PCLcan cause instability of the knee joint, arthritis, and substantialpain.

ACL reconstruction or repair typically includes the use of a tendongraft replacement procedure which usually involves drilling a bonetunnel through the tibia and up into the femur. Then a graft, which maybe an artificial ligament or harvested graft, such as a tendon, ispassed through a tibial portion of the tunnel (sometimes referred to as“the tibial tunnel”) across the interior of the joint, and up into afemoral portion of a tunnel (sometimes referred to as “the femoraltunnel”). One end of the ligament graft can then be secured in thefemoral tunnel and another end of the graft is secured in the tibialtunnel, at the sites where the natural ligament attaches.

A number of conventional surgical procedures exist for re-attaching suchligament graft to bone, which have advantages and certain drawbacks. Forexample, a fixation device in the form of an elongate “button,”sometimes referred to as a “cortical button” can be used for an ACLfixation to the femur or tibia. However, such devices are relativelywide, such that it is required to remove a substantial amount of bone inthe femur to drill a tunnel sized sufficiently to receive the devicetherethrough. This can complicate the surgery and extend its duration,as well as to cause inconvenience to the patient and delay healing.

Delivery of tissue fixation devices can also be difficult. For example,leading sutures that are wrapped around a tissue fixation device maybreak. Also, during delivery, the tissue fixation device may catch onthe edge of the bone tunnel and become embedded in the bone instead ofresiding on top of the lateral cortex.

Accordingly, there is a need for improved tissue fixation devices andtechniques for using such devices. There is also a need for improveddevices, systems, and methods for delivering such tissue fixationdevices.

SUMMARY

A system for delivering an implantable tissue fixation device isprovided that in some embodiments includes a tissue fixation devicehaving first and second elongate, substantially rigid support membersthat are discrete elements separated from each other, at least oneflexible member connecting the first and second rigid support members,at least one graft retention loop coupled to the tissue fixation device,and a drill pin. The tissue fixation device has changeable dimensionssuch that the device has a delivery configuration and a deployedconfiguration. The tissue fixation device has at least one dimensionthat is smaller in the delivery configuration than in the deployedconfiguration. The drill pin has a sidewall surrounding a cavity at aproximal end of the drill pin. The cavity is configured to fully seatthe tissue fixation device. The drill pin is configured to substantiallycontain therein the tissue fixation device when in the deliveryconfiguration, and the drill pin is configured to enable deployment ofthe tissue fixation device through the opening.

The system can vary in any number of ways. For example, the drill pincan have at least one longitudinally oriented opening in the sidewall incommunication with the cavity. The drill pin can have a proximal endwall in communication with the sidewall and the proximal end wall has aslot therein. The slot can be in communication with the opening andconfigured for passage of the at least one graft retention loop duringdeployment. In another example, the at least one flexible member caninclude a fabric.

The system can further include at least one third elongate,substantially rigid support member, and at least one second flexiblemember connecting the second and third rigid support members.

In some embodiments, the at least one flexible member can include aplurality of elongate connecting filaments extending between the rigidsupport members. The plurality of elongate connecting elements caninclude suture or wire. In one aspect, the rigid support members eachcan include a plurality of retaining elements used to couple theplurality of elongate connecting filaments to the rigid support members.

In one embodiment, the at least one graft retention loop can be coupledto the at least one flexible member and disposed around the rigidsupport members.

The system can further include at least one of first and second suturesremovably coupled to opposite ends of the at least one flexible member.The first and second sutures can extend in opposite directions along alength of the at least one flexible member.

In some aspects, a device for delivering an implantable tissue fixationdevice is provided. The device includes a drill pin having a proximalend and a distal end that includes a tissue-penetrating tip, a cavityformed within the drill pin at the proximal end thereof. The cavity isdefined in part by a sidewall of the drill pin. The sidewall isinterrupted by a longitudinally oriented opening in communication withthe cavity.

The device can vary in a number of ways. For example, the drill pin canbe configured to substantially contain in the cavity an expandabletissue fixation device when in an unexpanded configuration. In anotherexample, the drill pin can be configured to enable deployment of thetissue fixation device through the opening in the sidewall. In yetanother example, the tissue fixation device can have a first and asecond elongate, substantially rigid support member that are discreteelements separated from each other, and at least one flexible memberconnecting the first and second rigid support members.

In other aspects, a method for fixating a graft ligament into a bonetunnel is provided. The method includes forming a graft construct bycoupling the graft ligament to a tissue fixation device via a graftretention loop of the tissue fixation device; inserting the tissuefixation device in a collapsed, delivery configuration into a cavity ata proximal end of a drill pin, the cavity defined by a sidewallsurrounding at least part of the cavity, the cavity being configured tosubstantially contain the tissue fixation device therein; drilling thedrill pin into a bone to form a bone tunnel; deploying the tissuefixation device through the opening in the drill pin and passing thegraft construct through the bone tunnel with the tissue fixation devicein the delivery configuration; and positioning the tissue fixationdevice over a first end of the bone tunnel in a deployed configuration.The tissue fixation device includes first and at least one secondelongate, substantially rigid support members that are discrete elementsseparated from each other and at least one flexible member connectingthe rigid support members. The tissue fixation device is positioned overa first end of the bone tunnel in a deployed configuration such that therigid support members are spaced from one another by a distance greaterthan in the delivery configuration, and the graft retention loop and thegraft ligament extend into the bone tunnel.

The method can have any number of variations. For example, the drill pincan have a proximal end surface in communication with the sidewall, andthe proximal end surface can have a slot therein. The slot can be incommunication with the opening. Prior to deployment of the tissuefixation device, the at least one graft retention loop can pass throughthe slot.

The method can further include pulling the drill pin through the bonetunnel. The drill pin can be pulled using a pin puller.

In some embodiments, when in the deployed configuration, the tissuefixation device can be generally perpendicular with respect to the firstend of the bone tunnel. In other embodiments, the drill pin has alongitudinal axis and the tissue fixation device can be deployed throughthe opening at an angle with respect to the longitudinal axis. In yetother embodiments, the at least one flexible member can include aplurality of elongate connecting filaments extending between the rigidsupport members.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments described above will be more fully understood from thefollowing detailed description taken in conjunction with theaccompanying drawings. The drawings are not intended to be drawn toscale. For purposes of clarity, not every component may be labeled inevery drawing. In the drawings:

FIG. 1A is a perspective view of one embodiment of a tissue fixationdevice;

FIG. 1B is a top view of the tissue fixation device of FIG. 1A;

FIG. 1C is a exploded view of the tissue fixation device of FIG. 1A;

FIG. 2A is a side cross-sectional view of the tissue fixation device ofFIG. 1A in an uncompressed configuration;

FIG. 2B is a side cross-sectional view of the tissue fixation device ofFIG. 2A in a compressed configuration;

FIG. 3A is a plan view of another embodiment of a tissue fixation devicein an undeployed configuration prior to the device being passed througha femoral tunnel;

FIG. 3B is a perspective view representative of the tissue fixationdevice of FIG. 3A in a deployed configuration after the device is passedthrough a femoral tunnel;

FIG. 4 is a perspective view of an embodiment of a tissue fixationdevice including multiple rigid support members;

FIG. 5 is a perspective view of another embodiment of a tissue fixationdevice including multiple rigid support members;

FIG. 6A is a schematic side view of the tissue fixation device of FIG. 5in an uncompressed configuration;

FIG. 6B is a schematic side view of the tissue fixation device of FIG. 5in a compressed configuration;

FIG. 6C is a schematic side view of the tissue fixation device of FIG. 5having a load applied thereto;

FIG. 7A is a partial side view of an embodiment of a drill pin having anopening in a sidewall thereof;

FIG. 7B is an end view of the drill pin of FIG. 7A;

FIG. 8A is a side view of another embodiment of a drill pin having anopening in a sidewall thereof;

FIG. 8B is a side view of the of the drill pin of FIG. 8A with a tissuefixation device therein with a graft retention loop extending from theend thereof;

FIG. 9A is a side view of a portion of another embodiment of a drill pinhaving an opening therein;

FIG. 9B is an end view of the drill pin of FIG. 9A showing a slot in theproximal end wall of the drill pin;

FIG. 10 is a proximal end view of an embodiment of a drill pin having atissue fixation device therein;

FIG. 11 is a proximal end view of another embodiment of a drill pinhaving a tissue fixation device therein, wherein the tissue fixationincludes five rigid support members;

FIG. 12A is a partial schematic side view of the drill pin of FIG. 7Awith a tissue fixation device therein;

FIG. 12B is a schematic end view of the drill pin of FIG. 12A with thetissue fixation device therein;

FIG. 13 is a schematic side view of the drill pin of FIG. 12A with thetissue fixation device partially deployed from the drill pin;

FIG. 14 is a schematic end view of the drill pin of FIG. 12A with thetissue fixation device partially deployed from the drill pin;

FIG. 15 is a schematic view of the drill pin of FIG. 12A with the tissuefixation device almost fully deployed through the end and opening in thesidewall of the drill pin;

FIG. 16 is a schematic side view of an embodiment of the drill pin ofFIG. 9A having an end surface with a slot therein and a tissue fixationdevice seated in the cavity of the drill pin;

FIG. 17 is a schematic end view of the drill pin and tissue fixationdevice of FIG. 16;

FIG. 18 is a side elevation cross-sectional view of a knee having an ACLreconstruction procedure using a tissue fixation device and the drillpin of FIG. 7A; and

FIGS. 19A-19G are sequential side cross-sectional views of an embodimentof a drill pin and a tissue fixation device being deployed to a boneduring a surgical procedure.

DETAILED DESCRIPTION

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the systems and methodsdisclosed herein. One or more examples of these embodiments areillustrated in the accompanying drawings. Those skilled in the art willunderstand that the systems and methods specifically described hereinand illustrated in the accompanying drawings are non-limiting exemplaryembodiments and that the scope of the embodiments is defined solely bythe claims. Further, the features illustrated or described in connectionwith one exemplary embodiment may be combined with the features of otherembodiments. Such modifications and variations are intended to beincluded within the scope of the described embodiments.

The embodiments described herein generally relate to devices, systems,and methods for fixating tendon grafts during ligament reconstruction oraugmentation surgeries. The implantable tissue fixation device is onethat can move between different configurations such that at least one ofits dimensions can change. At the same time, the device has sufficientrigidity that allows it to withstand a load comparable to what largerdevices could withstand. The system includes a drill pin that can seatthe tissue fixation device during delivery. Methods of delivering thetissue fixation device using such drill pin are also provided.

Before describing the delivery system, devices, and method, we firstdescribe exemplary tissue fixation devices to which the system andmethod described herein are applicable. In particular, the exemplaryimplantable tissue fixation device is one that includes first and secondelongate, substantially rigid support members separate from one anotherand at least one flexible member connecting the rigid support members.The tissue fixation device further includes at least one graft retentionloop coupled to the tissue fixation device and configured to retain atissue graft in place when the device is implanted. At least onedimension of the tissue fixation device can vary. Thus, in someembodiments, prior to or following the tissue fixation device beingdeployed, the rigid support members can be spaced apart at a distancethat is equal or approximately equal to a width of the flexible member.The flexible member, which can be a single sheet or can be in the formof one or more filaments, can also be bent, rolled, folded, crimped, orotherwise manipulated so as to decrease a distance between the rigidsupport members. For example, the rigid support members can be broughtcloser together in a delivery configuration for passing the tissuefixation device through a bone tunnel to a point of fixation. In thisway, a bone tunnel having a smaller diameter, as compared to a bonetunnel diameter required to pass a conventional device, can be formed.

In the delivery configuration, the rigid support members can be disposedin a non-intersecting orientation with respect to one another. Thetissue fixation device is configured such that, after it is passedthrough the bone tunnel, it is positioned over an opening of the tunnelsuch that the rigid support members are similarly disposed in thenon-intersecting orientation with respect to one another.

The devices and methods described herein provide a number of advantagesover existing techniques for fixating tendon grafts. For example, asmentioned above, a bone tunnel of a reduced size can be formed, whichrequires removing less bone from the patient's body. This can decrease apossibility of complications at the surgical site and can ultimatelydecrease morbidity associated with the surgical procedure. In addition,because the overall tissue fixation device is more flexible and therigid support members can move with respect to each other, the devicecan be positioned against bone such that to better conform to the curvedsurface of the bone. In this way, the tissue fixation device can be lesspalpable by the patient, as compared to existing devices. Furthermore,the described tissue fixation device is simplified and it can be morecost-effective.

The described devices and methods can be used in conjunction with avariety of tendon grafts, including hamstring tendon grafts, and in avariety of different surgical contexts regardless of the type of tendongraft being used in a particular surgical procedure. The devices andmethods described herein can be utilized in connection with fixatinggrafts for repairing or replacing ligaments in a variety of joints. Insome embodiments, the devices and methods described herein haveparticular utility in cruciate ligament reconstruction procedures. Insome embodiments, the devices and methods described herein can beutilized for fixating tendon grafts for reconstruction procedures suchas, for example, the cruciate ligaments of the knee.

FIGS. 1A-1C illustrate one embodiment of an implantable tissue fixationdevice 100. The tissue fixation device 100 includes first and secondsubstantially rigid elongate support members 102, 104, and at least oneflexible member 106 connecting the first and second support members 102,104. As shown, the tissue fixation device 100 also has at least onegraft retention loop 108 coupled to the flexible member 106, as well asleading and trailing sutures 110, 111 also coupled to opposite ends ofthe flexible member 106. It should be appreciated that, in someembodiments, the tissue fixation device 100 can have one of the leadingand trailing sutures 110, 111 rather than both the leading and trailingsutures 110, 111.

As shown in FIGS. 1A-1C, the tissue fixation device 100 in anuncompressed configuration (e.g., prior to delivery and deployment) canbe generally rectangular. However, a person skilled in the art willappreciate that the tissue fixation device 100 can have any other shape.For example, in some embodiments, the tissue fixation device 100 can besquare, circular or oval. The shape of the tissue fixation device 100can be regular or irregular.

The tissue fixation device 100 has at least one changeable dimensionsuch that the device 100 has a delivery configuration and a deployedconfiguration. The substantially rigid support members 102, 104 providerigidity and structural support to the tissue fixation device 100, whilethe flexible member 106 is able to change its configuration to therebyallow the tissue fixation device 100 to adopt different configurations.Thus, at least one dimension (e.g., width) of the tissue fixation device100 can be smaller in the delivery configuration than in the deployedconfiguration, as discussed in more detail below. Although the size ofthe tissue fixation device 100 in the delivery configuration, and, insome embodiments, in both the delivery and deployed configurations canbe generally smaller than that of existing devices, the strength of thetissue fixation device 100 remains sufficient to withstand the load towhich it is subjected.

The substantially rigid first and second support members 102, 104 canvary in a number of ways. In the illustrated embodiment, as shown inFIG. 1C, the first and second support members 102, 104 are elongatediscrete elements separated from each other and that are configured toprovide structural support to the tissue fixation device 100 and thus toa graft. In the illustrated embodiment, the first and second supportmembers 102, 104 are retained within retention passages or pockets 112,114 formed from the flexible member 106. In other embodiments, the firstand second support members 102, 104 can be coupled to the at least oneflexible member 106 in other ways, as discussed below.

The support members 102, 104 can be generally cylindrical such that theycan have a circular or oval cross-section. It should be appreciated thatthe embodiments described herein are not limited to a specificconfiguration of the support members 102, 104. For example, the supportmembers 102, 104 can be generally planar such that they can have arectangular or square cross-sectional shape. Furthermore, although eachof the support members 102, 104 is shown in FIG. 1C as an elongatecomponent having no features formed therethrough or thereon, in someembodiments, each support member can have various features. For example,in some embodiments, the first and second support members can includeone or more surface features (e.g., ridges, prongs or other protrusions)that facilitate coupling of the support members to the flexible member.Furthermore, in embodiments wherein the flexible member is formed frommultiple elongate filaments extending between the support members, thefirst and second support members can include retaining features tocouple such elongate filaments thereto, as described in more detailbelow.

The first and second support members 102, 104 can remain substantiallyparallel to each other in both the delivery and deployed configurations.In the illustrated embodiment, the tissue fixation device 100 isconfigured such that the first and second support members 102, 104 maynot translate or translate only slightly relative to one another. Inother words, the first and second support members 102, 104 can remain atthe same position with respect to one another along a length of thetissue fixation device 100.

The size of the first and second support members 102, 104 can vary in anumber of ways. For example, the length of the first and second supportmembers 102, 104, which determines the overall length of the tissuefixation device 100, can vary depending on the requirements of anintended application. Generally, the overall length is in the range ofabout 5 mm to about 25 mm. In yet other embodiments, the length can varyfrom about 10 mm to about 15 mm. In one embodiment, the length is about12 mm. In the illustrated embodiments, the first and second supportmembers 102, 104 have the same length. However, it is understood thatthe first and second support members 102, 104 can have differentlengths. A diameter of a widthwise cross-section of the first and secondsupport members 102, 104 can vary depending on the requirements of anintended application. In one aspect, the diameter can be in the rangefrom about 0.5 mm to about 2.0 mm. In another aspect, the diameter canbe in the range of about 1.0 to about 1.1 mm. When a widthwisecross-sectional shape of the support members 102, 104 is different fromcircular or oval, the size of the cross-section is similar to the above.

The first and second support members 102, 104 can be formed from anysuitable material, and the individual members need not be formed fromthe same material. For example, they can be formed from a surgicalstainless steel, titanium alloy, or another biocompatible, sufficientlystrong metal that allows the first and second support members 102, 104to withstand the load to which they will be subjected. In someembodiments, the first and second support members 102, 104 are formedfrom a Chromium Molybdenum (Co—Mo) alloy. The first and second supportmembers 102, 104 can also be formed from non-metallic materials, whichmay be or may not be biodegradable materials. Non-limiting examples ofsuch non-metallic materials include a polyether ether ketone (PEEK),polylactic acid (PLA), biphasic tricalcium phosphate (bTCP), andBiocryl® Rapide® material composed of 30% osteoconductive β-TCP and 70%poly-lactide co-glycolide (PLGA). In some embodiments, the first andsecond support members 102, 104 can be formed from ceramics, such as,for example, aluminum oxide. The first and second support members 102,104 can be formed from one material or a combination of two or morematerials. The materials typically have a high strength such that theUltimate Tensile Strength is about 500 MPa and the Yield Strength isabout 215 MPa. However, the materials can be such that their UltimateTensile Strength and the Yield Strength can have other values. Thematerials used to form the first and second support members 102, 104 canbe such that the tissue fixation device 100 has a yield load in bendingthat varies from about 250 Newton (N) to about 2500 N, depending on aspecific application. In one embodiment (e.g., in which the tissuefixation device 100 is used for an ACL replacement procedure), the yieldload in bending of the tissue fixation device 100 can be about 1000 N.

The form and structure of the flexible member 106 connecting the firstand second support members 102, 104 can vary in a number of ways. In theillustrated embodiment, as shown in FIG. 1A-1C, the flexible member 106is in the form of a fabric sheet. However, in some embodiments, theflexible member 106 can be in the form of elongate connecting filamentsextending between the rigid support members, as discussed in more detailbelow. Regardless of its specific configuration, the flexible member canbe manipulated so as to change its configuration to thereby decrease adistance between the first and second support members 102, 104. In theillustrated embodiment, the flexible member 106 in the form of thefabric sheet can be rolled, bent, folded, collapsed, crimped, orotherwise manipulated so that a distance between the first and secondsupport members 102, 104 can be decreased. In this way, a width of thetissue fixation device 100 can decrease. In such a configuration, thetissue fixation device 100 can be passed through a bone tunnel having adiameter that is less than a diameter that would be required to pass aconventional tissue fixation device therethrough.

The flexible member 106 can connect the first and second support members102, 104 such that a distance at which the first and second supportmembers 102, 104 are spaced apart is changeable in a number of ways. Asshown in FIGS. 1A-1C, in the illustrated embodiment, the flexible member106 has first and second retaining passages or pockets 112, 114 formedon either side of a longitudinal axis A of the tissue fixation deviceand which are configured to retain the first and second support members102, 104 therein. It should be appreciated that FIG. 1A shows the firstand second support members 102, 104 visible at the openings 112 a, 114 aof the first and second pockets 112, 114 for illustration purposes only.It is understood, however, that both openings of each of the pockets112, 114 can be closed or closeable. In this way, the first and secondsupport members 102, 104 are unable to slide out of the pockets 112,114.

In the illustrated embodiment, the first and second pockets 112, 114 areformed by configuring the fabric forming the flexible member 106. Forexample, longitudinal sides of the fabric (which can be rectangular orsquare) can be rolled or folded towards a mid-portion of the fabric(which is also a mid-portion of the flexible member 106), and the foldscan be stitched or otherwise secured to the remainder of the fabric tothereby form the longitudinal pockets. As shown in FIGS. 1A-1C,longitudinal stitches 116, 118 are formed at a distance spaced apartfrom opposite sides of the flexible member 106 to form the pockets 112,114, respectively. In addition, transverse stitches 120 a, 120 b areformed to retain the first support member 102 within the first pocket112, and transverse stitches 122 a, 122 b are formed to retain thesecond support member 104 within the second pocket 114. However, itshould be appreciated that the first and second pockets 112, 114 can beformed in other ways, as embodiments described herein are not limited toa specific way of forming the pockets or otherwise retaining the supportmembers. For example, the flexible member 106 can be manufactured suchthat it can have the pockets 112, 114 or other retaining featurespreformed and configured to receive and hold therein the first andsecond support members 102, 104.

Forming the pockets can involve placing the first and second supportmembers 102, 104 at opposite longitudinal sides of the fabric androlling or folding the sides of the fabric over the support members 102,104, so as to enclose the support members 102, 104. Alternatively, thesupport members 102, 104 can be inserted into the pockets after thepockets are formed. Regardless of the specific way of forming thepockets, the first and second support members 102, 104 can each be heldtightly within a respective pocket.

The flexible member can connect the first and second support members inother ways as well. For example, in some embodiments, the flexiblemember 106 can include a plurality of slits, holes or other openingsalong longitudinal sides thereof. To couple the first and second supportmembers to one another, the flexible member can be passed through theopenings, e.g., by entering the openings at alternating sides of theflexible member 106. Additionally or alternatively, as mentioned above,the first and second support members can include one or more surfacefeatures (e.g., ridges, prongs or other protrusions) that can facilitateinterlocking between the support members and the flexible member. Thefirst and second support members can be coupled to the flexible memberin any other manner, such that the first and second support members donot separate from the flexible member during delivery and deployment ofthe device, and after the device is implanted.

The flexible member 106 can have various sizes and are dimensions(including length, width and thickness) and a person skilled in the artcan readily determine the appropriate size depending on the requirementsof a given application. The width (W) of the flexible member 106 in theuncompressed configuration of the tissue fixation device 100 (beforedelivery and deployment of the device 100) is shown in FIG. 1A and thewidth can range from about 2 mm to about 8 mm. In one embodiment, thewidth can be about 5 mm. The length (L) of the flexible member 106 shownin FIG. 1A can depend on the length of the first and second supportmembers 102, 104. Thus, the flexible member 106 can be long enough toretain the first and second support members 102, 104 in the retainingpockets 112, 114. For example, the length (L) of the flexible member 106can vary from about 5 mm to about 28 mm. In some aspects, the length canvary from about 10 mm to about 18 mm. In some aspects, the length canvary from about 12 mm to about 13 mm. In one aspect, the length (L) canbe about 12 mm.

The flexible member 106 can be made from a number of suitable materials,such as biologically inert and biocompatible fabrics. For example, theflexible member 106 can be manufactured from fabrics such aspolyethylene terepthalate (Dacron®) or polytetrafluoroethylene (PTFE, orGORE-TEX®). Alternatively, the flexible member 106 can be made fromresorbable plastic fibers such as, for example, polylactic acid (PLA).

Referring back to FIGS. 1A-1C, as mentioned above, the tissue fixationdevice 100 includes the graft retention loop 108 coupled thereto. Thegraft retention loop 108 is configured (in size, shape and strength) tohold a tissue graft passed through the loop when the tissue fixationdevice 100 is implanted. In the illustrated embodiment, the graftretention loop 108 is coupled to the flexible member 106 and disposedaround the rigid support members 102, 104. The graft retention loop 108can be coupled to the flexible member 106 by passing therethrough. Asshown in FIG. 1C, the graft retention loop 108 can be formed from asuture or a similar material having its opposite free ends coupledtogether at a knot 109. It should be appreciated that, the knot 109 canbe formed after the suture is passed through the flexible member 106. Itshould also be appreciated that the graft retention loop 108 can becoupled to the flexible member 106 using techniques that may not involveforming a knot. For example, the loop can be a continuous loop, or theends of the suture forming the loop can be joined together using a lapjoint, splice joint, or other technique. Additionally or alternatively,the ends of the suture can be glued together. Any other technique can beused as embodiments are not limited in this respect.

The graft retention loop 108 can have any suitable dimensions. In someembodiments, it can have a length (before forming a loop) in the rangeof about 10 mm to about 60 mm. In some embodiments, the length can rangefrom about 15 mm to about 25 mm. In one embodiment, the length can beabout 15 mm. The length of the graft retention loop 108 can be fixed.Alternatively, in some embodiments, the length of the graft retentionloop 108 can be adjustable such that it can be changed by a user whenthe tissue fixation device 100 is in use. For example, the graftretention loop 108 can be manipulated to increase its length when alonger loop is desired. As another example, a length of the graftretention loop 108 can be decreased if the uncompressed length is longerthan desired.

The thickness (diameter) of the material forming the loop can also varyand it is typically in the range from about 1 mm to about 4 mm. Also,the graft retention loop 108 can be formed from any suitable material(s)and it can be formed in a number of ways. For example, it can be acontinuous loop or it can be braided, woven, or otherwise formedconstruct. A person skilled in the art will appreciate that any varietyof materials (including ultra-high-molecular-weight polyethylene(UHMWPE)) can be used to form the loop, including those typically usedto form sutures. Further, the tensile strength at break can be about 50MPa and the tensile strength at yield can be about 20 MPa such that thematerial is sufficiently strong to serve its intended purpose of graftretention. The maximum tensile load of the entire construct can be inthe range from about 250 N to about 2500 N. It should be appreciatedthat the described embodiments are not limited to any specific graftretention loop.

The graft retention loop 108 can be formed from any suitable materials.For example, the loop 108 can be formed from a suture that can be anytype of suture. For example, the suture can be from size 0 to size 5,such as Orthocord® suture or Ethibond® suture. In some embodiments, thesuture can be formed from ultra-high-molecular-weight polyethylene(UHMWPE). In some embodiments, the suture can include high-molecularweight-polyethylene (HMWPE) or HMWPE with a co-braid (e.g., monofilamentpolypropylene, nylon or other co-braid). In some embodiments,monofilament sutures such as, for example, Monocryl® available fromEthicon, Inc., may be utilized. As another example, an absorbable suturesuch as Vicryl® (a copolymer made from 90% glycolide and 10% L-lactide)also available from Ethicon, Inc. may be used. The sutures used hereincan have any suitable amount and type of bioabsorbable material, whichcan depend on a particular surgical procedure and/or surgeonpreferences.

As shown in FIGS. 1A-1C, the flexible member 106 includes apertures oropenings 124, 126, formed at opposite sides of the longitudinal axis Aof the flexible member 106, and these are intended for passing the graftretention loop 108 therethrough so as to couple the loop 108 to thetissue fixation device 100. The openings 124, 126 can be pre-formed orthey can be formed as a suture forming the graft retention loop 108 ispassed through the flexible member 106. The openings 124, 126 can bereinforced by additional sutures placed around their perimeter, or inany other manner, so as to prevent fabric forming the flexible member106 from fraying and improve the rigidity of the openings.

It should be appreciated that the two openings 124, 126 formed throughthe flexible member 106 are shown by way of example only, as a singleopenings can be formed. As another example, the loop 108 can wrap aroundthe tissue fixation device 100, without passing through the flexiblemember. In some embodiments, a tissue fixation device can include agraft retention loop can be formed from a flexible member. For example,the flexible member can be tied to form a loop and it can be otherwiseconfigured into a loop-like shape.

The tissue fixation device 100 also includes leading and trailingsutures 110, 111 that assist in passing the device 100 through the bonetunnel and in “flipping” device 100 (i.e., transferring the device 100from a delivery configuration to a deployed configuration) after it ispassed through the tunnel, as discussed in more detail below. Theleading and trailing sutures 110, 111 can have any suitable length andcan be formed from any suitable materials. For example, in someembodiments, the leading suture 110 can be formed fromultra-high-molecular-weight polyethylene (UHWMPE) high strengthOrthocord® suture size 5, and the trailing suture 111 can be formed fromultra-high-molecular-weight polyethylene (UHWMPE) high strengthOrthocord® suture size 2. In some embodiments, one or both of theleading and trailing sutures can be from size 0 to size 5, such asOrthocord® suture commercially available from DePuy Mitek, and Ethibond®suture available from Ethicon, Inc. However, a person skilled in the artwill appreciate that the leading and trailing sutures 110, 111 can beformed from any suitable materials, including from the same type ofsuture.

The leading and trailing sutures 110, 111 can be coupled to the tissuefixation device 100 in a number of ways. In the illustrated embodiment,as shown in FIGS. 1A-1C, the flexible member 106 includes apertures oropenings 130, 131 for passing the leading and trailing sutures 110, 111therethrough. As shown, the openings 130, 131 are formed at oppositesides thereof and disposed approximately along the longitudinal axis Aof the flexible member 106. Like openings 124, 126 for retaining theloop 108, the openings 130, 131 can be pre-formed in the flexible member106 or they can be formed as the leading and trailing sutures 110, 111are passed through the flexible member 106 (e.g., using a needle). Theopenings 130, 131 can be reinforced in a suitable manner. Alternatively,the leading and trailing sutures can pass through a single aperture oropening.

As indicated above, the tissue fixation device 100 is configured suchthat the flexible member 106 can be folded, crimped, compressed, orotherwise deformed and the distance between the rigid support members102, 104 can thus decrease relative to the original (undeformed oruncompressed) configuration of the device to facilitate delivery. FIGS.2A and 2B illustrate the tissue fixation device 100 in an original,uncompressed configuration (FIG. 2A) and in a compressed configuration(FIG. 2B), which can be a deployed and/or delivery configuration. Asshown, in the original, uncompressed configuration, the rigid supportmembers 102, 104 can be disposed such that a distance D1 between theirmid-points is greater than a distance D2 between the mid-points in thecompressed configuration. The tissue fixation device 100 can be passedthrough a bone tunnel in the compressed delivery configuration in whichthe rigid support members 102, 104 maintained in a non-intersectingorientation with respect to one another, as shown in FIG. 2B. In thedelivery configuration, the rigid support members 102, 104 are disposedclose to each other such that the tissue fixation device 100 can bepassed through a bone tunnel having a reduced diameter.

After the tissue fixation device 100 is passed through the bone tunnel,as discussed in more detail below, it is placed over an opening in abone tunnel (not shown) in the compressed deployed configuration suchthat the graft retention loop 108 is used to retain a tissue graft 202.Thereafter, the device can be rearranged in a manner desired by thesurgeon. Typically, because the tissue graft 202 is tensioned due toload applied thereto such that the graft retention loop 108 extends intothe bone tunnel, the rigid support members 102, 104 tend to be broughtcloser together as the flexible member 106 forms one or more folds 204.As the rigid support members 102, 104 come closer together, they aremaintained in a non-intersecting orientation with respect to oneanother. It should be appreciated that, in the delivery configuration,the rigid support members 102, 104 can be positioned closer to oneanother as compared to their relative positions in the original,uncompressed configuration. Thus, a distance between the mid-points ofthe rigid support members 102, 104 in the delivery configuration can beequal or greater than D2 and less than D1. However, in some embodiments,in the delivery configuration, the rigid support members 102, 104 can bepositioned with respect to one another such that a distance betweentheir mid-points is approximately equal to the distance D1 in theuncompressed configuration of the tissue fixation device 100.

FIGS. 3A and 3B illustrate another embodiment of a tissue fixationdevice 300 including first and second substantially rigid supportmembers 302, 304 and a flexible member 306 in the form of a plurality ofelongate connecting filaments 306 a-306 e extending between the rigidsupport members 302, 304. Like tissue fixation device 100 (FIGS. 1A-1C),the tissue fixation device 300 also includes a graft retention loop 308coupled thereto such that it passes around both sides of the device, andleading and trailing sutures 310, 311 also coupled thereto.

The first and second rigid support members 302, 304 are substantiallyelongate elements coupled to one another via the flexible member 306such that a distance between the support members 302, 304 is changeable.Each of the rigid support members 302, 304 can include a plurality ofretaining elements used to couple the elongate connecting filaments 306a-306 e thereto. Thus, as shown in FIGS. 3A and 3B, the first supportmember 302 includes first retaining elements 312 a-312 e, and the secondsupport member 304 includes second retaining elements 314 a-314 e. Inthe illustrated embodiment, the first and second retaining elements 312a-312 e, 314 a-314 e are in the form of openings formed in the rigidsupport members 302, 304 and longitudinally spaced along a length of thesupport members 302, 304. The first retaining elements 312 a-312 e canbe spaced the same distance apart along the first support member 302,and the second retaining elements 314 a-342 e can be similarly spacedthe same distance apart along the second support member 304.

The openings can have a round or oval cross-sectional shape, and theycan be formed such that, in the uncompressed configuration, an openingin one of the support members is disposed opposite to an opening inanother one of the support members. A person skilled in the art willappreciate, however, that the retaining elements 312 a-312 e, 314 a-314e can be formed in the rigid support members 302, 304 in other manners,as embodiments are not limited in this respect. Furthermore, retainingelements having other configurations (e.g., hooks, protrusions or otherstructures) can be formed on or within the support members 302, 304.

The first and second rigid support members 302, 304 can be sized andconstructed similar to first and second rigid support members 102, 104(FIGS. 1A-1C), as discussed above. Also, the first and second rigidsupport members 302, 304 can be formed from materials similar to thoseused to form the first and second rigid support members 102, 104 whichare also discussed above.

In the illustrated embodiment, the elongate connecting filaments 306a-306 e connecting the first and second rigid support members 302, 304can each be formed from a separate element (e.g., suture or wire) suchthat the tissue fixation device 300 has an overall “ladder-like”configuration. However, in some embodiments, a single suture or wireelement can be passed through the retaining elements 312 a-312 e, 314a-314 e or coupled to via other retaining elements to the rigid supportmembers 302, 304. The single suture can be used to form a tissuefixation device having “ladder-like” configuration or a tissue fixationdevice in which elongate connecting filaments from a crisscrossedpattern between the support members.

The connecting filaments 306 a-306 e can be rigid such that, in adelivery configuration, the distance between the rigid support members302, 304 can decrease as they translate with respect to each other, asshown in FIG. 3B. In embodiments in which the connecting filaments 306a-306 e are formed from a flexible suture, wire, or other material(s),the connecting filaments 306 a-306 e can be compressed in a mannersimilar to flexible member 206 (FIGS. 2A and 2B) to allow the rigidsupport members 302, 304 to come closer together without translatingwith respect to each other.

As mentioned above, the connecting filaments 306 a-306 e of the flexiblemember 306 can be formed from a suture or wire. The suture can be anytype of suture. For example, the suture can be from size 0 to size 5,such as Orthocord® suture or Ethibond® suture. In some embodiments, thesuture can be formed from ultra-high-molecular-weight polyethylene(UHMWPE). In some embodiments, the suture can include high-molecularweight-polyethylene (HMWPE) or HMWPE with a co-braid (e.g., monofilamentpolypropylene, nylon or other co-braid). In some embodiments,monofilament sutures such as, for example, Monocryl® available fromEthicon, Inc., may be utilized. As another example, an absorbable suturesuch as Vicryl® (a copolymer made from 90% glycolide and 10% L-lactide)also available from Ethicon, Inc. may be used. The sutures used hereincan have any suitable amount and type of bioabsorbable material, whichcan depend on a particular surgical procedure and/or surgeonpreferences. In embodiments in which the connecting filaments 306 a-306e are formed from a wire, the wire can be formed from surgical stainlesssteel, titanium alloy, or other biocompatible metal, or polymer.

As shown in FIGS. 3A and 3B, the graft retention loop 308 can be coupledto the tissue fixation device 300 by being disposed around the rigidsupport members 302, 304. The graft retention loop 308 can additionallyor alternatively be coupled to the rigid support members 302, 304 in anumber of other ways. For example, the graft retention loop 308 can becoupled to a feature (not shown) formed on or in one or both of thesupport members 302, 304. As another example, the graft retention loop308 can be coupled to the rigid support members 302, 304 by passingaround or through one of the flexible connecting filaments 306 a-306 e,for example, around or through the filament 306 c or one or more ofother filaments.

The leading and trailing sutures 310, 311 can be coupled to the tissuefixation device 300 in a number of ways. For example, the leading andtrailing sutures 310, 311 can pass around one or more of the elongateconnecting filaments 306 a-306 e. Thus, in the illustrated embodiment,as shown in FIGS. 3A and 3B, the leading and trailing sutures 310, 311are coupled to the tissue fixation device 300 such that the leadingsuture 310 passes (e.g., loops) around the connecting filament 306 e atone end of the device 300 and the trailing suture 311 passes (e.g.,loops) around the connecting filament 306 a at the opposite end of thedevice 300. It should be appreciated that the locations of the leadingand trailing sutures can be reversed such that the leading suture 310passes around the connecting filament 306 a and the trailing suture 311passes around the connecting filament 306 e. Furthermore, as a personskilled in the art will appreciate, the leading and trailing sutures310, 311 can be coupled to the tissue fixation device 300 in other ways.For example, one or both of the leading and trailing sutures 310, 311can pass through one or more of the elongate connecting filaments 306a-306 e. Also, the leading and trailing sutures can loop more than onetime about one or more of the elongate connecting filaments 306 a-306 e.

The leading and trailing sutures 310, 311 can be formed from materialssimilar to those used to form leading and trailing sutures 110, 111 oftissue fixation device 100 (FIGS. 1A-1C), as discussed above.

In some embodiments, a tissue fixation device has more than two rigidsupport members. In such embodiments, the rigid support members can havea reduced diameter such that the tissue fixation device can move to acompressed configuration by being rolled into a tube-like configuration.FIG. 4 illustrates an implantable tissue fixation device 400 thatincludes a plurality of substantially rigid elongate support members 402a-402 g and a plurality of flexible members 406 a-406 f each connectingtwo of the support members 402 a-402 g. Although not shown, the tissuefixation device 400 also has at least one graft retention loop (whichcan be similar to graft retention loop 108 of FIGS. 1A-1C) coupled toone or more of the flexible members 406 a-406 g in a suitable manner.The tissue fixation device 400 can also have one or both of leading andtrailing sutures coupled to opposite ends thereof.

As mentioned above, the rigid support members 402 a-402 g can have asmall diameter, for example, about 0.1 mm. It should be appreciated thatseven rigid support members 402 a-402 g are shown in FIG. 4 by way ofexample only, since the tissue fixation device 400 can have other numberof rigid support members (e.g., three, four, five, six, eight or morethan eight). The larger the number of the rigid support members, thesmaller the diameter of each of the rigid support members. The rigidsupport members 402 a-402 g are connected to each other via flexiblemembers 406 a-406 g such that the rigid support members 402 a-402 gremain in a non-intersecting orientation with respect to one another inuncompressed and compressed configurations.

As shown in FIG. 4, each of the flexible members 406 a-406 g connectingrespective two of the rigid support members 402 a-402 g includesmultiple filaments. For example, the flexible member 706 a can be in theform of a plurality of filaments 407 a-407 h as shown in FIG. 4. In theillustrated embodiment, the filaments 407 a-407 h can be spaced atapproximately equal distances away from each other along a length of therigid support members 402 a-402 g. However, the filaments 407 a-407 hcan be disposed along a length of the rigid support members 402 a-402 gat other intervals.

As shown, each of the filaments 407 a-407 h can include one or moreelements movably coupled to each other. In the illustrated embodiment,each of the filaments is in the form of two triangular-shaped elementsconnected to one another so as to form a cross-hatching pattern. Thefilaments can also be formed by interconnected rings or any otherelements. It should be appreciated that eight filaments 407 a-407 htogether forming a flexible member are shown in FIG. 4 by way of exampleonly, as the rigid support members 402 a-402 g can be coupled to oneanother using any suitable number of any other type(s) of filaments. Thefilaments can be formed from a metal, fabric or any other material.

The support members 402 a-402 g are connected via the flexible members406 a-406 g such that adjacent support members can be displaced withrespect to each other. The support members 402 a-402 g can be connectedvia the flexible members 406 a-406 g such that the support members 402a-402 g at least partially restricted from translating with respect toone another. Alternatively, the flexible members 406 a-406 g can connectthe support members 402 a-402 g such that adjacent support members 402a-402 g can be translated with respect to one another.

The tissue fixation device 400 can move from an uncompressed to acompressed configuration by being rolled into a tube-like configuration.In such configuration, the tissue fixation device 400 can be passedthrough a bone tunnel (e.g., a femoral tunnel) having a relatively smalldiameter. For example, the tissue fixation device 400 can be passed inthe compressed configuration through a femoral socket and a passingtunnel which will be discussed in more detail with respect to FIGS. 18and 19A-G. After the tissue fixation device 400 passes through the bonetunnel, the device 400 can be moved to an uncompressed or partiallyuncompressed configuration to support the tissue fixation loop and agraft coupled thereto. For example, the tissue fixation device 400 canbe unrolled into a flat or partially flat configuration.

FIG. 5 illustrates another embodiment of a tissue fixation device 500which is similar to tissue fixation device 400 (FIG. 4). As shown, thetissue fixation device 500 includes a plurality of substantially rigidelongate support members collectively referred to as rigid elongatesupport members 502 and a plurality of flexible members each connectingtwo of the support members 502 and collectively referred to as flexiblemembers 506. The flexible members 506 can be similar to the flexiblemembers 406 a-406 g (FIG. 4) or they can have other configuration.

In the illustrated embodiment, as shown in FIG. 5, a distance betweeneach adjacent support members 502 can be relatively small. The width (W1in FIG. 5) of the tissue fixation device 500 in the uncompressedconfiguration (before delivery and deployment of the device 500) canrange from about 2 mm to about 8 mm. In one embodiment, the width can beabout 5 mm. The length (L1 in FIG. 5) of the tissue fixation device 500can depend on the length of the rigid elongate support members 502 andit can vary from about 5 mm to about 28 mm. In some embodiments, thelength L1 can vary from about 10 mm to about 18 mm. In some embodiments,the length can vary from about 12 mm to about 13 mm. In one embodiment,the length L1 can be about 12 mm. A width of each of the flexiblemembers 506 can depend on a diameter of the support members 402 a-402 g.For example, in embodiments in which the diameter of each of the supportmembers 702 a-702 g is about 0.1 mm, the width of each of the flexiblemembers 506 can vary from about 0.03 mm to about 0.08 mm.

FIG. 6A shows the tissue fixation device 500 in an uncompressedconfiguration, and FIG. 6B shows an exemplary embodiment of the tissuefixation device 500 in a compressed (rolled-up) configuration. Thetissue fixation device 500 can be delivered to an implantation site insuch a configuration.

FIG. 6C illustrates the tissue fixation device 500 in the deploymentconfiguration, with a graft retention loop 508 coupled thereto in asuitable manner. As shown in FIG. 6C, because a tissue graft (not shown)coupled to the graft retention loop 508 is tensioned due to load appliedthereto, the rigid support members 502 tend to be brought closertogether as the flexible members 506 allow the rigid support members 502to be replaced with respect to one another. Thus, in such configuration,the tissue fixation device 500 is no longer in the rolled-up into a tubeand, at the same time, the device 500 has a configuration different froma fully flattened configuration, as shown in FIG. 6B. A person skilledin the art will appreciate that the tissue fixation device 500 is shownin FIGS. 6B and 6C by way of example only and that the tissue fixationdevice 500 can be compressed in different other ways in its deploymentand delivery configurations.

Tissue fixation devices of the type described above can be implantedaccording to various techniques. Particularly useful techniques aredescribed in U.S. patent application Ser. No. 14/730,484, entitled“Tissue Fixation Device,” which is hereby incorporated by reference inits entirety. Additional devices, systems, and methods for delivering animplantable tissue fixation device are described below.

In one aspect, a suitable delivery device generally includes a drill pinhaving a proximal end and a distal end that includes atissue-penetrating tip. A cavity is formed within the drill pin, such asat the proximal end thereof. The cavity is defined in part by a sidewallof the drill pin and the sidewall is interrupted by a longitudinallyoriented opening in communication with the cavity. The drill pin isconfigured to substantially contain in the cavity an expandable tissuefixation device (such as one of the type described above), which can behoused in the cavity in an unexpanded or delivery configuration. In someembodiments, the cavity is configured to fully seat the tissue fixationdevice. Further, the drill pin is configured to enable deployment of thetissue fixation device through the opening. The delivery systemgenerally includes a tissue fixation device such as described herein, atleast one graft retention loop coupled to the tissue fixation device,and a drill pin having a cavity configured to seat the tissue fixationdevice therein. Methods of fixating a graft ligament into a bone tunnelusing such devices and systems are also provided and are discussedbelow.

The disclosed devices, systems, and methods for delivering a tissuefixation device have a number of advantages. For example, fewer surgicalsteps, such as reaming steps, are required when using the drill pindescribed herein, and the tissue fixation device can be deployed duringthe drilling step. As another example, a surgeon has more control whenpulling the tissue fixation device through the bone tunnel because thetissue fixation device is seated in a drill pin and is thus notsusceptible to being caught on the bone tunnel wall during deployment.As such, the deployment location of the drill pin is more certain.Tissue fixation device delivery can also be effected in a morecontrolled manner because instead of winding suture around a pair offorceps, a pin pusher can be used to pull the drill pin along with thetissue fixation device and graft retention loop through the bone tunnel.

FIGS. 7A and 7B illustrate one embodiment of a drill pin 700 fordelivering a tissue fixation device such as tissue fixation devices 100,300, 400, 500 described above. The drill pin 700 is generally anelongate structure having a proximal end 702 and a distal end having atissue-penetrating tip (not shown) and a cavity 704 therein. Thelongitudinally oriented opening 708 leading to cavity 704 is defined atits lateral edges by sidewalls 706 and may be defined by an endwall 707at its distal edge. There is no proximal boundary for the opening in theembodiment of FIGS. 7A and 7B.

With further reference to FIGS. 7A and 7B, the drill pin 700 has twolongitudinally oriented openings 708 that are on opposite sides of thedrill pin 700 and extend to the open proximal end 702 of the drill pin700. That is, there is no proximal wall abutting the openings 708. Inother embodiments, the drill pin 700 can have a single opening, or threeor more openings. Multiple openings 708 can be positioned in anyconfiguration along the circumference or outer edges of the drill pin700, and the opening(s) 708 can have any suitable dimensions such thatdrill pin 700 is configured to enable deployment of a tissue fixationdevice through the opening 708 in the sidewall 706. Thus, generally,opening 708 is elongate and sized and shaped so that the tissue fixationdevice can be inserted into and delivered from opening 708.

Although shown to be at the proximal end of the drill pin 700, opening708 can be located in any portion of the drill pin 700. For example, oneor more openings can be positioned in a distal portion, a proximalportion, or a middle portion of the drill pin. In one embodiment, atleast one opening is positioned in the proximal portion of the drill pinas shown, for example, in FIG. 7A.

The proximal end of the drill pin can have various configurations. Forexample, the proximal end of the drill pin 700 shown in FIG. 7A is open.In other embodiments, the proximal end of the drill pin can include aproximal end wall, which can be closed or which can possess one or moreopenings therein. In another aspect, the one or more openings in theproximal end wall can be in the form of an eyelet or slot or any otherdesired size or shape that is configured to accommodate passage of atleast one graft retention loop coupled to the tissue fixation deviceduring deployment of the tissue fixation device.

FIGS. 8A and 8B illustrate another embodiment of a drill pin 800 fordelivering a tissue fixation device. As shown in FIGS. 8A and 8B, thedrill pin 800 has a proximal end 802 and tissue-penetrating tip 812 at adistal end 814 thereof. Like the drill pin described above with respectto FIGS. 7A and 7B, drill pin 800 has a cavity 804 formed at least inthe proximal end 802 thereof, and at least one longitudinally orientedopening 808 formed in sidewall 806 of the drill pin is in communicationwith cavity 804. Opening 808 is defined by lateral sidewalls 806, distalendwall 807, and proximal end wall 816 of the drill pin 800. In thisembodiment, the proximal end wall 816 is partially open to accommodatethe graft retention loop 810, which as shown in FIG. 8A, has a graftretention loop 810 extending through proximal endwall 816 from a tissuefixation device (not shown) contained in a cavity 804 of the drill pin800. Like the drill pin described above with respect to FIGS. 7A and 7B,cavity 804 and opening 808 can also be positioned in the middle portion816 of the drill pin or closer to the distal end of the drill pin.Moreover, drill pin 800 can have more than one opening 808 thatcommunicates with cavity 804.

FIGS. 9A and 9B show yet another embodiment of a drill pin 900 in whichan opening 908 in drill pin 900, in the form of a window in sidewall 906of the drill pin 900, communicates with an internal cavity of the drillpin. Moreover, a proximal portion of the opening is defined by aproximal end wall 916. Like proximal end wall 816 of FIG. 8A, proximalend wall 916 of drill pin 900 is partially open. However, as shown inFIGS. 9A and 9B, proximal end wall 916 of has an opening in the form ofslot 918 that communicates with opening 908, whereas opening 808 insidewall 806 of FIG. 8A is not in communication with an opening in theproximal end wall 816.

Regardless of which variation of the drill pin is utilized, the tissuefixation device can be inserted into the drill pin in various ways. Forexample, the tissue fixation device can be inserted into the drill pinvia the distal end, proximal end, or through the opening in thesidewall. In designs where the proximal end of the drill pin is open,the tissue fixation device can be inserted through the open proximalend. The tissue fixation device can also be angularly oriented andinserted into the cavity directly through the opening in the event thatthe tissue fixation device has a length that is greater than the lengthof the opening. The tissue device can also be deployed from the drillpin in similar manners, as described in more detail below.

FIGS. 10-17 show exemplary embodiments of tissue fixation devices atleast partially seated within the drill pins of the type describedherein. It is understood that FIGS. 10-17 are intended to generallyillustrate the manner in which the tissue fixation devices is seatedwithin the drill pins, but for ease of illustration the tissue fixationdevices are shown to be spaced away from inner walls of the drill pin, acondition that is not likely to occur in reality.

FIG. 10 illustrates an embodiment of drill pin 900, viewed from itsproximal end, having a tissue fixation device 500 disposed therein andconfigured in an unexpanded or delivery configuration and containedwithin cavity 904 of drill pin 900. Although not shown in FIG. 10, thesidewall 906 of the drill pin 900 has a longitudinal opening 908 formedtherein as shown, for example, in FIG. 9A. In the illustrated embodimentthe tissue fixation device 500 includes support members 502 connected byflexible members 506. Although tissue fixation device 500 is shown inFIG. 10 to have seven rigid support members 502, it is understood thatthe tissue fixation device 500 can include less than or more than sevensupport members 502. In the embodiment illustrated in FIG. 10, the graftretention loop 508 that is coupled to the tissue fixation device 500 isalso contained within the cavity 904 of the drill pin 900. As explainedbelow, however, other configurations can be used for the tissue fixationdevice and the drill pins.

FIG. 11 illustrates another embodiment of a drill pin 900, viewed fromits proximal end, having a tissue fixation device 1100 therein. Asillustrated, tissue fixation device 1100 includes five rigid supportmembers 1102 a-1102 e connected by flexible members 1106, and in FIG. 11it is disposed in its delivery configuration as it is rolled up insidethe drill pin 900.

When the tissue fixation device is disposed within the drill pin in adelivery configuration, the rigid support members are typically disposedin a non-intersecting orientation relative to one another. Thus, therigid support members can be substantially parallel to one another. Asso configured, the rigid support members are disposed a first distanceaway from one another that is less than a distance between the rigidsupport members in an uncompressed configuration. This reduced distancebetween substantially rigid support members allows the support membersand flexible member coupled therebetween to have a reduced diameter soas to enable the tissue fixation device to be housed within the drillpin.

One skilled in the art will appreciate that dimensions of the drill pinand tissue fixation device can be any that are suitable for a desiredapplication. Moreover, the dimensions of the tissue fixation device inits delivery configuration will depend on the dimensions of the drillpin through which it is delivered, and the dimensions of the tissuefixation device in its deployed configuration will depend on therequirements of the surgical procedure with which it is used and theanatomy in which it is placed. In one embodiment, the tissue fixationdevice has a length of about 12 mm, each rigid support member of thetissue fixation device has a diameter of about 0.5 mm, and the drill pinhas an outer diameter of about 2.4 mm and an inner diameter of about 2mm. The diameter of a widthwise cross-section of the support members ofthe tissue fixation device contributes to the overall size of the tissuefixation device and this dimension can vary. In the example of FIG. 11,the drill pin 900 has an inner diameter I_(D) and an outer diameterO_(D). In the illustrated delivery configuration, the three rigidsupport members 1102 e,a,c of the tissue fixation device 1100 aredisposed within inner cavity 904 of drill pin 900 and extend along thelength of the drill pin. As shown, rigid support members 1102 e,a,c areseparated by each other and inner surface 920 of the sidewall 906 bydistances D₁-D₄. The inner diameter of the drill pin should be largeenough to accommodate the tissue fixation device in a clearance fit. Inone embodiment, inner diameter I_(D) can at least be equal to the sum ofthe distances D₁-D₄ between support members 1102 e,a,c and inner surface920 of sidewall 906 of drill pin 900 plus the number of rigid supportmembers along a diameter of the drill pin multiplied by the maximumdiameter of the rigid support member (X_(max)). In other words,I_(D)=(D₁+D₂+D₃+D₄)+3(X_(max)).

The length of the tissue fixation device can also vary. Although thelength of the tissue fixation device is less than the length of thecavity of the drill pin, the length of the tissue fixation device can begreater than the length of an opening in the sidewall of the drill pinas long as the tissue fixation device can be inserted into the cavitywhen in the delivery configuration.

FIGS. 12A and 12B illustrate an embodiment of drill pin 700 of FIGS. 7Aand 7B having tissue fixation device 1100 of FIG. 11 disposed therein.In this embodiment, like FIGS. 7A and 7B, drill pin 700 has an openproximal end 702 with two longitudinal openings 708 in sidewall 706 ofthe drill pin, as shown in FIG. 12A. As explained above, sidewall 706surrounds cavity 704 of the drill pin, and the longitudinally orientedopenings 708 in the sidewall 706 are in communication with the cavity704. As shown in FIG. 12A, drill pin 700 is configured to substantiallycontain therein the tissue fixation device 1100 when it is in thedelivery configuration.

As shown in the proximal end view of the drill pin 700 in FIG. 12B, thetissue fixation device 1100 has five generally parallel rigid supportmembers 1102 that are connected by flexible members 1106. In thisembodiment, two legs of a graft retention loop 1108 are coupled to thetissue fixation device 1100 and are also shown in FIG. 12B. The tissuefixation device 1100 is shown in an unexpanded, delivery configurationwithin drill pin 700. In this undeployed configuration, the tissuefixation device 1100 has a diameter that is less than the diameter ofthe drill pin 700 so that it is able to fit within the drill pin in aclearance fit. Further, in this embodiment, the tissue fixation device1100 has a length that is greater than the length of the openings 708 inthe sidewall 706 of the drill pin 700. In other embodiments, however,the tissue fixation device 1100 can have a length that is the same as orless than the length of the opening 708 in the sidewall 706.

FIGS. 13-15 illustrate an embodiment of tissue fixation device 1100being partially deployed from drill pin 700, which is furtherillustrated in FIGS. 12A and 12B. As shown in FIG. 13, tissue fixationdevice 1100 is being partially deployed through opening 708 in sidewall706 and the open proximal end 702 of drill pin 700. FIG. 14 shows tissuefixation device 1100 being partially deployed through the proximal end702 of the drill pin of FIG. 12A. As shown, rigid support members 1102are oriented at an angle such that they are not parallel to longitudinalaxis 720 of drill pin 700 during the deployment process. In FIG. 15,tissue fixation device 1100 is almost fully deployed through proximalend 702 and opening 708 in sidewall 706 of drill pin 700. Only the endsof support members 1102 are shown in FIG. 15 as the tissue fixationdevice 1100 is oriented upon deployment so as to be generallyperpendicular to longitudinal axis 720 of drill pin 700.

A person skilled in the art will appreciate that tissue fixation device1100 can be deployed at various angles with respect to the longitudinalaxis of the drill pin. In one embodiment, the tissue fixation device1100 can be deployed through opening 708 in drill pin 700 at an angle soas to facilitate rotating the tissue fixation device 1100 into anorientation that is perpendicular to the drill pin so that the tissuefixation device spans a bone tunnel upon implantation. Tissue fixationdevice 1100 can also be deployed at an angle to prevent the tissuefixation device 1100 from entering the bone tunnel. Once the tissuefixation device is at least partially deployed, graft retention loop1108 can be pulled to rotate the tissue fixation device 1100 into adesired final position. A person skilled in the art will appreciate thatother suitable methods of creating a downward force can be employed tofacilitate rotation of the tissue fixation device 1100 duringdeployment.

FIGS. 16 and 17 show another embodiment of tissue fixation device 1100disposed in drill pin 900, which is a drill pin of the type illustratedin FIGS. 9A and 9B having a proximal end wall 916 with a slot 918therein. As shown in FIG. 16, tissue fixation device 1100 has a lengththat is less than the length of opening 908 in sidewall 906 of drill pin900 and when the tissue fixation device is in its rolled, unexpandedconfiguration within the drill pin it has a diameter that is less thanthe inner diameter of drill pin 900. Thus, in its unexpandedconfiguration, tissue fixation device 1100 can easily be insertedthrough opening 908 in sidewall 906 and into cavity 904 of the drillpin. Because slot 918 in the proximal end 902 of drill pin 900 is notsufficiently large for deployment of the tissue fixation devicetherethrough, tissue fixation device 1100 can only be deployed throughopening 908 in sidewall 906 for the embodiment of FIGS. 16 and 17.During deployment of tissue fixation device 1100 from drill pin 900, atleast one graft retention loop 1108 can pass through slot 918 whiletissue fixation device 1100 can pass through opening 908 in sidewall906, which is in communication with the slot 918. As discussed abovewith respect to FIGS. 13-15, tissue fixation device 1100 can likewise bedeployed from drill pin 900 at an angle to facilitate rotating thetissue fixation device 1100 into the perpendicular orientation relativeto the longitudinal axis of the drill pin so that the tissue fixationdevice lies across a bone tunnel following implantation.

Some embodiments provide a method for fixating a graft ligament within abone tunnel using the tissue fixation device and the drill pinsdescribed herein. In one embodiment, the method generally includesforming a graft construct by coupling the graft or graft ligament to atissue fixation device via a graft retention loop of the tissue fixationdevice. Any suitable tissue fixation device and graft including thosedisclosed herein may be used to form the graft construct. The methodalso includes utilizing a drill pin of the type shown, for example, inthe embodiments of FIGS. 7A-9B that has a tissue fixation devicedisposed in a cavity of the drill pin in a collapsed, deliveryconfiguration. During such a procedure the drill pin is embedded into abone to form a bone tunnel, the tissue fixation device is deployedthrough the opening in the drill pin, and the graft construct is passedthrough the bone tunnel with the tissue fixation device in the deliveryconfiguration, and the tissue fixation device is positioned over a firstend of the bone tunnel in a deployed configuration. These steps can beperformed in any suitable order. For example, in one embodimentdescribed below, the graft can be coupled to the tissue fixation devicevia the graft retention loop after formation of the bone tunnel.

The methods described herein can be used in various surgical proceduresincluding, for example, ligament reconstruction surgery involvingfixation of anterior or posterior cruciate ligaments. The disclosedtechniques can be adapted for other surgical procedures as well. Forexample, the described devices and methods can be used foracromioclavicular joint reconstruction and ankle syndesmosis. Thedevices and methods can be used for anastomosis and other surgerieswhere it is required to bring together two (or more) soft tissues, softtissue and bone tissue, or two bone tissues need to be brought or heldtogether.

FIGS. 18 and 19A-G illustrate the use of the drill pin and tissuefixation devices described herein in a ligament reconstruction surgeryinvolving fixation of the anterior cruciate ligament. FIG. 18illustrates a patient's leg 1801 in the course of an ACL reconstructionprocedure performed thereon using a tissue fixation device 1800, such astissue fixation device 100 (FIGS. 1A, 1B, 2A, and 2B) or tissue fixationdevice 300 (FIGS. 3A and 3B), and drill pin 700 (FIGS. 7A and 7B). Insome embodiments, other drill pins such as drill pins 800, 900,described above, can be used in accordance with this method. FIG. 18shows tissue fixation device 1800 deployed on the lateral femoral cortex1840 and a graft or graft tendon 1806 disposed in femoral bone socket1824 and tibial bone tunnel 1828.

Surgical techniques for ligament reconstruction are well known.Generally, the method includes forming a bone tunnel to receive thegraft tendon 1806 therein. A bone tunnel for an ACL reconstructionprocedure in a patient's leg can be formed by drilling a tibial tunnelthrough the tibia, as known in the art. A femoral tunnel is then drilledsuch that the diameters of the femoral and tibial tunnels areappropriate to snugly fit the graft construct therethrough. In theembodiments described herein, because of the smaller size of tissuefixation device 1800 itself as well as drill pin 700 containing thetissue fixation device 1800 as compared to existing devices, a passingtunnel having a diameter that is less than a diameter of a passingtunnel required to pass therethrough a conventional device can beformed.

In the illustrated embodiment, as shown in FIGS. 18, 19A, 19B, and 19C,a bone tunnel 1820 in the patient's leg 1801 is formed that includes afemoral tunnel or socket 1824 and a tibial bone tunnel 1828. In theillustrated embodiment, a drill pin 700 is used to drill a relativelysmall diameter bone tunnel through the femur 1822. A diameter of suchbone tunnel drilled using the drill pin 700 can be in the range of about1 mm to about 5 mm. In one embodiment, the tunnel diameter is about 2.4mm. This step forms a passing bone tunnel 1826 shown in FIGS. 18, 19A,and 19B that extends from the condylar notch of the femur laterally tothe lateral cortex.

FIGS. 19A and 19B generally show an enlarged view of drill pin 700forming femoral bone tunnel 1826. FIG. 19A shows the tissue penetratingtip 712 at the distal end 714 of the drill pin 700 being introduced intoa bone such as femur 1822, shown in FIG. 18, to form bone tunnel 1826.Drill pin 700 has tissue fixation device 1800 seated therein at itsproximal end (not shown). FIG. 19B shows drill pin 700 inserted afurther distance into the bone and through the opposite side, e.g., thelateral cortex 1840, of the femur 1822 to complete bone tunnel 1826.

Next, the larger diameter femoral bone socket 1824 can be formed throughthe femur 1822, sized so as to receive the graft tendon 1806 therein.The femoral bone tunnel 1826 can be formed using, for example, acannulated drill or reamer advanced over the drill pin 700, or using anyother suitable technique. The drill pin 700 can remain in the bonetunnel 1826 during formation of the femoral bone socket 1824. FIG. 19Cshows drill pin 700 extending through bone tunnel 1826 with a femoralbone socket 1824 formed in a portion of the femur 1822 closer to theproximal end of the drill pin 700. FIG. 18 illustrates a tunnel 1820 infemur 1822 including femoral bone socket 1824 sized to accommodate grafttendon 1806 and a smaller diameter superior portion or passing channelor bone tunnel 1826 formed by drill pin 700 that houses tissue fixationdevice 1800 in a delivery configuration. The diameter of the femoralbone socket 1824 can be in the range of about 6 to about 12 mm. In oneembodiment, the diameter of the femoral bone socket 1824 is about 9 mm.

Once the femoral bone socket 1824 is created, the formation of the bonetunnel for the procedure is complete. As indicated above, the passingbone tunnel 1826 is formed in the femur superiorly to the femoral bonesocket 1824 by drilling the drill pin 700 through the femur. Thus, it isnot required to form a separate passing tunnel. In contrast, a techniqueusing a conventional tissue fixation device without the drill pin 700described herein would require an additional step of forming a largerpassing tunnel having a diameter of about 4.5 mm. With the techniquesdescribed herein, the passing bone tunnel 1826 can have a diameter inthe range of about 2.4 mm to about 4.4 mm, for example, whichcorresponds to an outer diameter of a drill pin used to form the passingbone tunnel 1826.

The above steps can be applied when the tissue fixation device isdelivered via a transtibial (TT) portal approach which can be used, forexample, when delivering a tissue fixation device having a fixed oradjustable graft retention loop. In the TT portal approach, as discussedabove, a tibial tunnel can be drilled in a desired manner. The drill pindescribed herein can then be drilled into the femur at a desiredlocation via the tibial tunnel, as generally shown in FIGS. 19A and 19B.

In another embodiment, tissue fixation device 1800 can be delivered viaan anteromedial (AM) portal approach which can be used, for example,when delivering the tissue fixation device with an adjustable graftretention loop 1808. The AM portal approach involves first drillingdrill pin 700 into femur 1822 at the center of the ACL footprint or atanother desired location via the AM portal and then drilling a tibialbone tunnel 1828 into tibia 1830. The bone tunnel 1826 can be formed inthe femur as described above and shown in FIGS. 19A and 19B. After bonetunnel 1826 is formed, the drill pin can then be overdrilled to adesired distance, leaving adequate bone shelf laterally to form femoralbone socket 1824 as shown in FIG. 19C. Drill pin 700 can then beadvanced further into femur 1822 until the proximal end of the drill pincontaining tissue fixation device 1800 rests inside femoral bone tunnel1826, as shown in FIG. 19D. Drill pin 700 can remain in bone tunnel 1826as tibial bone tunnel 1828 shown in FIG. 18 is drilled using anysuitable technique.

Drill pin 700 can then be moved in a retrograde manner to exit the kneejoint via the AM portal. Graft retention loop 1808, which is coupled tothe tissue fixation device 1800, can then be extended from tissuefixation device 1800 out of drill pin 700 and into the femoral bonesocket 1824, as shown in FIG. 19E.

Next, drill pin 700 can be advanced further through femur 1822 untilgraft retention loop 1808 is accessible in a joint. An arthroscopicgrasper or another suitable tool can be used to pull graft retentionloop 1808 inferiorly through tibial bone tunnel 1828. Graft tendon 1806can then be loaded onto the graft retention loop 1808, as shown in FIG.19E. Graft tendon 1806 can be loaded in any suitable manner, includingby techniques described herein. For example, as understood by a personskilled in the art, graft construct 1804 can be formed by coupling grafttendon 1806 to tissue fixation device 1800 via graft retention loop 1808of tissue fixation device 1800. This can be done after bone tunnel 1820and femoral bone socket 1824 are formed.

Once graft 1806 is loaded on graft retention loop 1808 (using the AM orTT portal approach or any other suitable method), as shown in FIG. 19E,drill pin 700 can be advanced further into femur 1822 so that graft 1806passes through tibial bone tunnel 1828 and joint space, and into femoralbone socket 1824, as generally shown in FIGS. 19D and 19E. FIG. 19Dshows the proximal end of drill pin 700 in femoral bone socket 1824 withtissue fixation device 1800 seated in cavity 704 of drill pin 700. FIG.19E illustrates the proximal end 702 of drill pin 700 and tissuefixation device 1800 advanced further into femur 1822 with graftretention loop 1808 and a portion of graft 1806 in femoral bone socket1824.

As shown in FIG. 19F, drill pin 700 is advanced through bone tunnel 1826until tissue fixation device 1800 contained therein extends beyondfemoral cortex 1840 above an opening 1832 of passing bone tunnel 1826.Drill pin 700 can be pulled through the bone tunnel 1826 using a pinpuller or other suitable instrument.

When the proximal end of drill pin containing the tissue fixation devicehas passed through the lateral cortex 1840, as shown in FIG. 19F, tissuefixation device 1800 can be released from the drill pin 700 and thedrill pin 700 can be removed from the femoral cortex 1840. In oneembodiment, a loop adjustment suture (not shown) can exit the skin withthe drill pin. In another embodiment, the loop adjustment suture cantrail down past the graft and through the tibial bone tunnel.

In this embodiment, tissue fixation device 1800 is deployed throughopening 708 in drill pin 700 as graft 1806 is pulled through the femoralbone socket 1824 to opening 1832 of bone tunnel 1826. Tissue fixationdevice 1800 is deployed from cavity 704 of drill pin 700 at an anglewith respect to longitudinal axis 720 of drill pin 700.

In embodiments where the drill pin has a slot on the end surfacethereof, graft retention loop 1808 can extend through the slot and passthrough the slot as tissue fixation device 1800 is deployed.

Tissue fixation device 1800 is deployed by pulling on graft retentionloop 1808 that connects drill pin 700 to graft 1806. Tissue fixationdevice 1800 can be released from drill pin 700 when significantresistance is felt which indicates that graft 1806 is fully engaged withthe top of femoral bone socket 1824. At this point, tissue fixationdevice 1800 is in a position to exit femoral cortex 1840 and drill pin700 can then be pulled out of femur 1822, as shown in FIG. 19F. In oneembodiment, the connection of drill pin 700 and tissue fixation device1800 can be configured such that tissue fixation device 1800automatically disengages from drill pin 700 at a specific tensile load.

In another embodiment, cavity 704 can be closer to the middle of drillpin 700 with respect to longitudinal axis 720 of drill pin 700. Cavity704 can be positioned such that the proximal end of drill pin 700 ispositioned at the entrance to the femoral tunnel prior to deployingtissue fixation device 1800 from drill pin 700.

In some embodiments, cavity 704 of drill pin 700 need not communicatewith an opening in sidewall 706 of drill pin 700. In fact, drill pin 700need not have any openings in sidewall 706 of drill pin 700 and insteadcavity 704 communicates only with an opening at the proximal end ofdrill pin 700. Drill pin 700 can be sized so that there is a sufficientretention force to hold tissue fixation device 1800 in place, but notdislodge the tissue fixation device 1800 when a pulling force is appliedto drill pin 700.

Upon deployment, tissue fixation device 1800 is “flipped” such it ispositioned over and across opening 1832, as shown in FIG. 19G. Thetissue fixation device can be flipped in any suitable manner that movesthe tissue fixation device from an angled position as shown in FIG. 19Fto the position shown in FIG. 19G that is generally parallel to thesurface of femur 1822. For example, tension can be applied to a suture(not shown). Creating a downward force vector, particularly one that isnon-parallel to the longitudinal axis of the drill pin, can facilitatemaneuvering the tissue fixation device.

As shown in FIG. 19G, in the deployed configuration, graft retentionloop 1808 with graft 1806 coupled thereto extend into bone tunnel 1826.As explained above, when tissue fixation device 1800 is in the deployedconfiguration, it is generally perpendicular with respect to the firstend of bone tunnel 1826. Also, the rigid support members (such assupport member 102, 104 shown in FIGS. 1A and 1B) of the tissue fixationdevice 1800 are disposed a second distance away from one another thatcan be greater than the first distance between the rigid support memberswhen they are in the delivery configuration. In the deployedconfiguration, the rigid support members remain disposed in thenon-intersecting orientation relative to one another.

While the distance between the rigid support members in the deployedconfiguration is greater than that in the delivery configuration, thedistance between the rigid support members in the deployed configurationcan be less than a distance between the rigid support members in theuncompressed configuration of the tissue fixation device 1800. Tensionapplied to graft 1806 during the procedure causes tension to be alsoapplied to tissue fixation device 1800 such that the rigid supportmembers tend to move closer together. It is to be understood that theflexible members can be in a configuration (e.g., compressed, deformed,folded, crimped, etc.) that is different from its uncompressedconfiguration so as to allow the distance between the rigid supportmembers to decrease relative to that in the uncompressed configuration.However, in some embodiments, the distance between the rigid supportmembers in the deployed configuration can be the same as that in theuncompressed configuration of tissue fixation device 1800.

The support members can be in any orientation when they are positionedover opening 1832, however they generally do not intersect. Although thesupport members are substantially rigid, they can have some degree offlexibility or malleability such that tissue fixation device 1800 can bepositioned over opening 1832 so as to conform to the shape of thelateral cortex. In this way, tissue fixation device 1800, onceimplanted, can be less palpable as compared to existing devices. In thedeployed configuration, as shown in FIG. 19G, tissue fixation device1800 sits on femur 1822 in a sideways orientation with graft retentionloop 1808 and graft 1806 extending medially through passing bone tunnel1826 and into socket 1824. Graft retention loop 1808 passes around bothsides of tissue fixation device 1800 such that it is supported by boththe support members. However, in some cases, the graft retention loopcan pass over one side of the device so as to be supported by one of thesupport members. An opposite end of graft 1806 can be placed into atibial bone tunnel 1828 in the leg's tibia 1830 and held in place with asuitable anchor 1834. After tissue fixation device 1800 is implanted,any leading and trailing sutures can be removed.

Graft 1806 can be held in place within bone socket 1824 by graftretention loop 1808. In one embodiment, graft retention loop 1808 can beof a fixed length. Another embodiment can include a loop adjustmentsuture that can exit the skin with drill pin 700, or can trail pastgraft 1806 and through tibial bone tunnel 1828. For adjustable looptissue fixation devices, a loop adjustment suture can be pulled untilgraft 1806 is fully engaged with the femoral tunnel and tissue fixationdevice 1800 is resting on the lateral cortex of femur 1822, as shown inFIGS. 18 and 19G.

After deployment of tissue fixation device 1800 and graft 1806 in bonesocket 1824, a tibial fixation can then be performed in any desiredmanner. An end of graft 1806 opposite bone socket 1824 can be placedinto a tibial bone tunnel 1828 in the leg's tibia and held in place witha suitable anchor 1834.

It is understood that graft tendon 1806 can be any suitable type ofgraft. For example, an autograft, which is a portion of the patient'sown tissue that would replace the damaged natural ligament, can be used.The autograft is often a hamstring tendon, though other tendons can beused (e.g., a patellar tendon). The tendon graft can also be anallograft obtained from a donor. The graft tendon can be prepared in asuitable manner well known to those skilled in the art, which caninvolve cleaning and measuring the graft, and then reinforcing free endsthereof.

It is also to be understood that in various figures graft tendon 1806 isnot shown to scale as the graft tendon actually has thicker dimensionssuch that it substantially entirely fills the bone tunnel (e.g., femoralbone socket 1824) in which it is received. Graft tendon 1806, onceimplanted, contacts the bone in which the bone tunnel is formed suchthat graft 1806 grows into and merges with the bone for a permanentrepair.

It should be appreciated that although illustrated embodiments providesystems, devices, and methods for orthopedic surgeries, such as, forexample, ligament reconstruction surgery involving fixation of anterioror posterior cruciate ligaments, the techniques can be adapted for othersurgical procedures as well. For example, the described devices andmethods can be used for acromioclavicular joint reconstruction and anklesyndesmosis. The devices and methods can be used for anastomosis andother surgeries where it is required to bring together two (or more)soft tissues, soft tissue and bone tissue, or two bone tissues need tobe brought or held together.

Having thus described some examples of the described embodiments,various alterations, modifications, and improvements will readily occurto those skilled in the art. Such alterations, modifications, andimprovements are intended to be within the spirit and scope of thedescribed embodiments. Accordingly, the foregoing description is by wayof example only, and not intended to be limiting.

What is claimed is:
 1. A device for delivering an implantable tissuefixation device, comprising: a drill pin having a proximal end and adistal end that includes a tissue-penetrating tip, a cavity formedwithin the drill pin at the proximal end thereof, the cavity beingdefined in part by a sidewall of the drill pin, the sidewall beinginterrupted by a longitudinally oriented opening in communication withthe cavity.
 2. The device of claim 1, wherein the drill pin isconfigured to substantially contain in the cavity an expandable tissuefixation device when in an unexpanded configuration.
 3. The device ofclaim 1, wherein the drill pin is configured to enable deployment of thetissue fixation device through the opening in the sidewall.
 4. Thedevice of claim 3, wherein the tissue fixation device has a first and asecond elongate, substantially rigid support member that are discreteelements separated from each other, and at least one flexible memberconnecting the first and second rigid support members.
 5. A method forfixating a graft ligament within a bone tunnel, comprising: forming agraft construct by coupling the graft ligament to a tissue fixationdevice via a graft retention loop of the tissue fixation devicecomprising first and at least one second elongate, substantially rigidsupport members that are discrete elements separated from each other andat least one flexible member connecting the rigid support members;inserting the tissue fixation device in a collapsed, deliveryconfiguration into a cavity at a proximal end of a drill pin, the cavitydefined by a sidewall surrounding at least part of the cavity, thecavity being configured to substantially contain the tissue fixationdevice therein; drilling the drill pin into a bone to form a bonetunnel; deploying the tissue fixation device through the opening in thedrill pin and passing the graft construct through the bone tunnel withthe tissue fixation device in the delivery configuration; andpositioning the tissue fixation device over a first end of the bonetunnel in a deployed configuration such that the rigid support membersare spaced from one another by a distance greater than in the deliveryconfiguration, and the graft retention loop and the graft ligamentextend into the bone tunnel.
 6. The method of claim 5, wherein the drillpin has a proximal end surface in communication with the sidewall, theproximal end surface having a slot therein, the slot in communicationwith the opening, and wherein prior to deployment of the tissue fixationdevice, the at least one graft retention loop passes through the slot.7. The method of claim 5, further comprising pulling the drill pinthrough the bone tunnel.
 8. The method of claim 7, wherein the drill pinis pulled using a pin puller.
 9. The method of claim 5, wherein, when inthe deployed configuration, the tissue fixation device is generallyperpendicular with respect to the first end of the bone tunnel.
 10. Themethod of claim 5, wherein the drill pin has a longitudinal axis and thetissue fixation device is deployed through the opening at an angle withrespect to the longitudinal axis.
 11. The method of claim 5, wherein theat least one flexible member comprises a plurality of elongateconnecting filaments extending between the rigid support members.